The present invention relates to a new and improved seal assembly and more specifically to a seal assembly which includes a seal holder having an annular groove in which a seal member is disposed.
Various known seal assemblies have been used in association with rotatable shafts of hydraulic motors or pumps. These motors or pumps may have a construction generally similar to the construction disclosed in U.S. Pat. Nos. 4,219,313 and 5,061,160.
Because of the high cost of PNF (trademark) (phosphonitrilic fluoroelastomer) synthetic rubber, it is desirable to minimize the amount of PNF (trademark) used in a seal assembly. However, it is desirable to use PNF (trademark) special purpose synthetic rubber as the active portion of a hydraulic seal assembly in order to obtain the advantages of having a relatively soft and durable synthetic rubber to form a seal against a hard member. In order to minimize the cost of a seal assembly, it is also preferred to eliminate metal reinforcing elements and/or garter springs. Although the garter springs are relatively low in cost, they must be installed after the molding process and sometimes pop off and are lost.